Sectional core



Mal,` 20; 1923. i 1,449,085..

- H. H. BRAND.

SECTIONAL CORE.

y FILED FEB.15,1921.

x 75 f@ Z.

Patented Mar. 20, T923.;

NETE@ STATES erratas ics.

HAROLD H. BRAND, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE `ASSIGrNMENTS, TO

ALUMINUM MANUFACTURES, INCORPORATED, OF CLEVELAND, OHO, A CORPO- RATION OF DELAWARE.

SECTIONAL CORE.

Application filed February 15, 1921. Serial No. 445,078.

To all wiz-ovm t may concern Be it known that- I, HAROLD H.BRAND. a citizen of the United States, residing at Cleveland, in the county of Cuyahoga, State of Ohio, have invented a certain new and usefulA Improvement in SectionalCoi-es, of which the following is a speciii'cation, reference being` had therein. to the accompany-- from the casting without damage to any parts thereof.

Another object is to provide a sectional core for lpiston molds, the sections of which core, which partly or wholly surround inwardly projecting wrist pin bosses. may be removed from engagement therewith by tiltL ing in the casting and may be withdrawn wise movement.

Other objects will be pointed out in the following specification.

While the form of core disclosed in the patent above cited is 'relatively cheap and easy to make and has a long life as compared with cores composed of -a greater number of parts, its use has been somewhat limited heretofore. The side sections must L0- 'be vmaintained substantially vertical while they are being moved inwardly to clear internal projections lon the casting and thus avoid damaging the hot, east metal. To permit such movement the inner end surface of the casting should be conca-ve and the projections should be relatively short with sharply tapered exterior surfaces. The care required 1n removal of the side sections even when the interior surface of the casting is properly designed, to avoid damage to the projections tends to slow up the production 'of castings and to increase correspondingly the cost thereof.

My improvedV core, however, greatly eX- tends the scope of usefulness of cores of this from the cast-ing by lateral and vthen endgeneraltype and at the same time retains their many advantages. Internal projections may be cast with a small exterior taper and of a length limited only by the space required between the inner ends of the projections for withdrawal of the core sections, while the inner end wall of the casting need not be concave. Removal of the side core sections from the casting is rendered quick and easy and damage to the projections is entirely avoided.

-The manner in which these advantages are obtained is briefly as follows. The core sections which core out the casting4 between the bosses and head wall are provided with sweeping curved surfaces or properly inclined plane surfaces which merge into the boss recess surfaces and the exterior side surface of the sections and which are of such configuration that these surfaces draw away from the casting when the core sections are tilted therein.

Although my invention is capable of use in various forms I have chosen, for purposes of illustration to show and describe one niodtication in which it is clearly disclosed.

ln the drawings attached to and constituting a part of this specification,

Fig. l. is ,a side elevation partly in section of a. mold equipped with athree part core. the casting, riser and gate cavities being filled with cast metal. Fig. 2 is a. fragmentary sectional view taken on line 2;-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 but showing the manner of removing the core sections from the casting.

Fig. 4 is a cross section of the core and parts of the mold taken on line 4-4 of Fig.

Fig. 5 is a view similar to Fig. 4 but taken on line 5-5 of Fig. 2.

Fig. 6 shows in elevation one of the side core sections provided with a boss recess' formed inv accordance with my invention.

ySince this invention constitutes an im provenient of certain elements of the structure shown and described in the above mentioned patent, those parts which are commonto the patented structure and to the device disclosed in this application will'be described only very briefly.

In the drawings 1 indicates the usual base of a mold for internal combustion engine pistons. The side members 2 seat upon the to` surface'of the base and'are'each provi ed in their meeting faces with'recesses which together form gate and riser cavities 3 Sand 4, respectively, and also with other-v recesses which in conjunction wit-h a surface of base 1 form a casting cavity 5. The

core, which is indicated as an entirety by 6, consists of three sections, 7, 8, and 9. They the top surface of the mold halves and 4thereby to support the assembled mold in the casting cavity 5. Each side section 7 and 9 has anexterior curved side surface 15,.end surface 17 and plane inner side surface 118,

the surfaces 17 and 18 intersecting to form` edge 19.

The' usual inserts 10 are secured in the mold halves by screws 1011, one `insert carry- Iing a key 11 suitably disposed-to engage with a keyway 11a in one of the core sections to position the assembled core properly in the casting cavity. Core pins 12 extending through the mold halves, contact with the core in the'casting cavity, and serve to core out the wrist pin bossesof the casting.

The assembled core has its outerside surfaces and one end surface shaped to provide the inner head and side walls of the casting cavityv 5 which in this cas'e is 'for a piston wit-h inwardly projecting bosses 13 and' a strenghtening rib 14 extending from one boss to and diametrically across the head and then to the other boss. A recess 14:L formed in the end and side surfaces of the assembled core permits the casting of this rib 14: on the inner surface of the piston.

Each'side core section has formed in its outer sidefsurface a recess 13"L vin which a boss 13 may be cast. The side walls of these recesses 13a have a slight inward'taper suiiicient to permit the sections to be withdrawn from contact with the bosses when the casting has-solidified. This taper is practically uniform around the boss recess except between a plane transverse to the length of the core section and passing through the center of the recesses and the end of the co-re section, where the side of the core section is cut away to form a recess 16.l This recess is substantially equal to or slightly greater than the boss recess at its junction ltherewith and becomes narrower as'it approaches the end of the core section. The recess extends into the core section' as far as the inner end surface of the boss recess from which it curves circumferentially and longitudinally of the coresection outwardly to4 the side surface' of the core section with which it merges on a line resembling a parabola. The curvature of each relief 16 4is irregular but on a central plane lengthwise of the -core section and passing through the boss recess 13 it is regular and constitutes part ofv a. circle having a center located well outside the side core section.:

`The radius 'of this curved surface i 16 'should be greater than the distance fromthe surface tothe inner end edge 19of, theside" section so that when the section pivots on edge 19 in the casting the relief 16 will draw away from the casting. In Fig. 2 is indicated the radius describing the boss re'- cess while in Fig. 3 the movement of the relief 16 away from the castings is indicated.

In operationmy improved form of core.

is assembled with molds of the -type shown in the above mentioned patent by first inserting the side sections 7 and 9 in casting cavity 5 and then placing'the center section 8 therebetween and clamping the mold halves together. The core pins are then inserted and the molten metal poured into the gate until it fills the casting-and riser cavities.

.When the cast metal has cooled sufficiently to permit withdrawal of the core, the core pins are removed, the clamps on the lmold haives are'loosened slightly and section 8 of the core is removed from the casting by withdrawing it longitudinally. The top of one side section 7 is then pushed inwardly until it approaches or contacts with the opposite side section 9 the other end of the section remaining in'contact with the inner head wall of the casting and pivoting there- -on alon vits inner end edge 19 which is formed y the intersectionA of the end and inner side surfaces 17 and 18 respectively. This tilting movement causes the surface of relief 16 yto draw away from the walls of the casting due to the fact that this surface is described by a radius' which is longer than the distance from the said surface to the inner end edge 19 of the core sect-ion. After the section is tilted to the position shown in Fig. 3 the inner end of the section may be moved laterally toward the opposite side section sufficiently to clear the boss 13 and then moved longitudinally out of the casting. The opposite or secondside section is removed in similar manner.

While I have described one form of core in detail I have done so merely for purpose of illustration. I do not wish to be limited to the details thereof since many different embodiments of the invention may be made by those skilled in the art without departing from the scope of my invention which is defined by what is claimed.

What is claimed: e 1. I n a mold for casting pistons having linwardly extending bosses, the combination of a permanent mold body having an opening the side and bottom walls of which form the outer walls of a casting cavity, and a sectional core comprising a central section and side sections extending into the casting cavity, the side and inner end surfaces of the said core forming the inner walls of the.

casting cavity, and boss recesses in the said side core sections having curved surfaces between the-recesses and the inner end of the core sections adapted to draw away from the bosses of a piston casting when the side sec.- tions are-tiltedA transversely in the said cast- 2. lin a mold for casting pistons having inwardly extending bosses, the combination of a permanent mold body having an opening t-he side and bottom walls of whichform the outer walls of a casting cavity, and a sectional core comprising a central section and side sections extending into the casting cavity, the side and inner` end surfaces of the said core forming the inner Walls of the casting cavity, and having boss. recesses in the said side core sections with surfaces curved from the ends of the boss recesses to the outer surfaces of the core sections, the said curved surfaces extending toward the inner end of the co-re from the boss recesses, and being curved about the centers of curvature lying outside the said core sections.

3. ln a mold for casting pistons having inwardly extending bosses, the combination of a permanent mold body having an opening the side and bottom walls of' which form the outer walls of a casting cavity, and a sectional core comprising a central sec.- t-ion and a section arranged on either side thereof and extending into the casting cavity, the side and end surfaces of the said core forming the inner walls of the casting cavity, each side section having a boss recess, each said recess having a surface curved longitudinally of the core and adapted to draw away from a boss cast in the` recess when the outer end of the said core section is tilted transversely of the casting cavity.

4c. 1n a mold for casting pistons having inwardly extending bosses, the combination of a permanent mold body having a casting cavity, a .permanent core comprising a center section and a sectionarranged at either side thereof, the outer side and end walls of the said sections cooperating to form the inner walls of the casting cavity, and means extending from the outer end of each of the said sections for supporting the sections in the casting cavity and permitting the outer end of the side sections to be tilted transversely of the casting cavity.

5. ln a mold for casting pistons having inwardly extending bosses, the combination of a permanent mold body having a casting cavity, a permanent sectional core comprising a center section and a section arranged at either side thereof, the outer side and inner end walls of the said sections cooperating to form the inner Walls of the castthe combination of a. permanent mold body" having a casting cavity, a sectional core comprising a central section and side sections in the casting cavity, recesses in the side sections for forming inwardly extending projections on the casting, thev central section being movable out of the casting byendwise movement, and the side sections each being movable out of the casting by being tilted transversely of the casting and then moved laterally to clear the said projections, followed by endwise withdrawal.

7. A permanent sectional core for molds for casting pistons comprising a central section and a side section on either side thereof, a boss recess having curved surfaces formed'in each of said side sections, the said curved surfaces being adapted to draw ,away from bosses cast therein when the sections are tilted transversely of the piston casting.

8. A permanent sectional core for piston molds comprisinga cent-ral section and a side section arranged on either side of the said central section, a bossrecess in each side section formed, in part, with a surface curving 'circumferentially and longitudinally of the section from the inner end of the recess to the outer surface of the section.

9. A permanent sectional core for piston molds comprising a central section and a side section arranged on either side of the said central section, a. boss recess in each side section, the portion of the surface of each said recess, which lies between a plane tranverse t0 the core and passing through the center of the recess and the inner end of the core, being curved longitudinally and circumferentially of the said section from th'e inner end surface of the said recess to the outer side surface of the said core sections.

10. A permanent sectional core for cup shaped castings having inwardly extending oppositely disposed projections. comprising a central section and a side section arranged on either side thereof, a recess in each side section for the said projections, the portion of the surface of each said recess lying between the center of the recess and the inner end of the core being curved longitudinally and circumferentially of the said section,

the longitudinal curvature having a radius greatertlian the distance from said surface to tlle inner end edge of the core section.

11. A core section for cup shaped castings, provided in its outer surface and adjacent the inner end with a recess for form ing an` inwardly extending projection on a casting, the surface of the said recess being curved circmferentially and longitudinally of the section between the' recess and the inner end of the section substantially as and for the purpose set forth.

l2. A core section for cup shaped castings, provided in its outer surface and adjacent the inner end with an inwardly extending recess for forming an inwardly extending projection on a casting, a portion of the surface ot the said recess being curved longitudinally of) the section from the inner end of the recess toward the inner end of the section on a radius of curvature greater than the. distance from said Surface to the inner end edge of tliesaid section.

In testimony whereof, l hereunto affix my signature. i i HAROLD H. BRAND. 

